N-112 Concept Immunity & Infectious Disease Nursing PDF

N-112- CONCEPT IMMUNITY & INFECTIOUS DISEASE NURSING. Mr. Elizalde M. Baldueza RN, MAN Lecturer ORGANS & TISSUE OF THE IMMUNE SYSTEM 1) BONE MARROW- specialized soft tissue filling the spaces in cancellous bone of the epiphysis, responsible for: a) r...

N-112- CONCEPT IMMUNITY & INFECTIOUS DISEASE NURSING. Mr. Elizalde M. Baldueza RN, MAN Lecturer ORGANS & TISSUE OF THE IMMUNE SYSTEM 1) BONE MARROW- specialized soft tissue filling the spaces in cancellous bone of the epiphysis, responsible for: a) releasing mature B lymphocytes into the blood circulation, b) moving T lymphocytes from the bone marrow to the thymus. 2) THYMUS- located in the mediastinum, primary central gland of the lymphatic system. Primary function is allowing T lymphocytes to develop before migrating to the lymph nodes & spleen. 3) LYMPH NODES- perform important functions; a) transporting lymph, a transparent sometimes faintly yellow & slightly opalescent fluid that carries varying numbers of WBC (chiefly lymphocytes & a few RBC) collected from tissues through out the body, flows in the lymphatic vessels thru the lymph nodes & added to the venous circulation. ORGANS & TISSUE OF THE IMMUNE SYSTEM b) filtering & phagocytizing ( processing & killing antigens) c) generating lymphocytes & monocytes. 4) SPLEEN- functions; a) removing worn-out erythrocytes from blood b) storing blood & platelet c) filtering & purifying blood 5) TONSILS & ADENOIDS- they are positioned in food & air passages-likely areas of microbial access. A mucoid lymphatic tissues defend the body against microorganism. 6) HEMATOPOIETIC SYSTEM- bone marrows & lymphatic tissue, a tissues that produce blood cells including those involved in immunologic defense ( leukocytes)  THE STRUCTURES OF HEMATOPOIETIC SYSTEM BLOOD VESSELS: arteries- carry blood away from the heart to the periphery; veins- carry blood to the heart; capillaries- lined with squamous cells, connect veins and arteries and lymphatic system- part of vascular system, collects the extravasated fluid from the tissues and returns it to the blood Blood –forming organs: a. Bone marrow- primary function: hematopoiesis; blood cells: start as stem cells, then mature to different , specific types of cells. The formed elements of blood or blood components: erythrocytes (RBC), leukocytes(WBC), thrombocytes (platelets).  THE STRUCTURES OF HEMATOPOIETIC SYSTEM Two kinds of bone marrow: red- functioning marrow, for hematopoiesis found in ribs, vertebral column, and other flat bones, erythroid, myeloid, and thrombocytic production site; also produces lympocytes and macrophages yellow- not involved in hematopoiesis, found in the hollow interior of the middle portion of long bones, consisting mainly of fat cells. In cases of severe blood loss, the body can convert yellow marrow back to red marrow to increase blood cell production. THE STRUCTURES OF HEMATOPOIETIC SYSTEM b. Spleen- largest lymphatic organ, blood filtration system and reservoir, important in phagocytosis, graveyard or RBC, removes misshapen (badly shaped or deformed) and unwanted parts of erythrocytes, hematopoietic site in fetus, produces lymphocytes and monocytes c. liver- for erythropoiesis during fetal life and if bone marrow’s erythropoietic activity is insufficient, for bile production Kupffer cells- reticuloendothelial cells that function as histiocytes (fixed macrophages) Phagocytic activity, iron storage, synthesis of clotting factors, synthesis of anti-thrombins  IMMUNE SYSTEM AND IMMUNITY IMMUNE- derived from a latin word “immunis” means free from burden or taxes. - a physiologic mechanism which endow an individual with the capacity to recognize material as foreign to itself & to neutralize, eliminate, or metabolize them with without injury to its own tissue. THE IMMUNE RESPONSE - the body develops an immune response whenever it recognizes a substance as foreign, a TOTAL IMMUNE RESPONSE includes the following; 1) Antibody production ( HUMORAL IMMUNITY) 2) Activation of cellular components ( CELLULAR IMMUNITY) for sensitized lymphocytes production. 3) Activation of certain WBC & tissue macrophage cells to phagocytize foreign materials & 4) Activation of serum complement proteins, resulting in death of foreign cells.  Characteristics of IMMUNE SYSTEM a. Self or non-self RECOGNITION- normally recognizes host cells as non-antigenic and responds only to foreign and potentially harmful agents, living or non-living as antigens. b. ANTIBODY PRODUCTION (diversity and specificity of action)- diverse in the ability to respond and the same time produces specific antibodies for specific antigens for destruction. c. MEMORY- recalls type of antigen, remembers antigens that have invaded the body in the past, allowing a quicker response. d. Self-regulation- monitors its own performance, turning itself on when antigens invade and turning itself off when infection is eradicated. (3) FUNCTIONS OF IMMUNE RESPONSES; 1) DEFENSE- against physical injury & infection 2) HOMEOSTASIS- involves removing “worn-out” self components. 3) SURVEILLANCE- deals with the identification & destruction of mutant cells. A DAMAGED IMMUNE SYSTEM may; 1) produce antibodies against the body’s own proteins, a development of an autoimmune disease. 2) results in hypersensitivity or allergic reactions 3) damage various organs or joints by allowing accumulation of immune response components; this is known as immune complex disease. 4) result in some deficiency of an immune response component, rendering the individual incapable of eliciting a normal immune response to any foreign substance, as in AIDS.  ANTIGENS & IMMUNOGENS ANTIGENS- a substance that owing to its chemical configuration, reacts with an antibody. IMMUNOGEN- any substance that induces a detectable immune response (humoral, cellular or both) when introduced into a host. - our immune system recognizes most proteins, bacteria, viruses & parasites that are not part of the normal body environment “foreign” - foreign substances elicit an immune response are called antigens or immunogens. HAPTENS- are smaller substance that can also elicit an immune response when combine with higher- weight antigenic substance. Ex. Penicillin & other medication that can initiate an immune response.  ORGANS and TISSUES OF IMMUNE SYSTEM a. Hematopoietic system (Bone marrow) – production site of RBC,s WBC,s and platelets. It’s primary function is hematopoiesis (formation of blood cells); particularly B lymphocytes mature in BM and distributed into circulation and moving T lymphocytes from BM to the thymus b. Thymus – is a single unpaired gland that is located in the mediastinum and is the primary gland of the lymphatic system. Creates hormone thymosin- stimulates the red bone marrow to produce T lymphocytes or T cells. Its primary function is allowing the T lymphocytes to develop before migrating to the lymph nodes and the spleen ORGANS and TISSUES OF IMMUNE SYSTEM c. Lymph nodes and vessels: perform several important functions such as: to drain fluids from tissue spaces and return it to the blood, transporting lymph, filtering and phagocytizing antigens, generating monocytes , lymphocytes and develop antibodies that are important to immunity. Lymphocytes – the main warriors of the immune system; they monitor for presence of antigen and mount an attack against them. Located in the tonsils, spleen, liver, lungs, bones, brain and spinal cord. d. Spleen functions include: largest lymphatic organ, removing worn out erythrocytes by macrophages, storing blood and platelets, filtering and purifying blood. ORGANS and TISSUES OF IMMUNE SYSTEM e. Tonsils, adenoids and other mucoid lymphatic tissues: defend the body against microorganisms and other harmful substances that enter thru mouth and nose f. Peyer’s patches- found in the wall of small intestines (ileum); Peyer’s patches and the tonsils are part of collection of small lymphoid tissues g. Kupffer cells also called as Browicz-Kupffer cells – are reticuloendothelial cells that function as histiocytes (fixed macrophages) found in the liver protecting upper resp. tract and GIT from attacks of foreign matter  CLASSIFICATION OF IMMUNITY I. SPECIFIC IMMUNITY a. HUMORAL IMMUNITY(anti-body mediated) – provided by antibodies present in the body’s humors, or fluid. * Characterized by production of antibodies by the B lymphocytes in response to a specific antigen. It is the one of the two forms of immunity that respond to bacteria and other foreign antigens. * When a B cells are confronted with a specific type of antigen, it transform into a plasma cells that produce antibodies known as Immunoglobulins CLASSES OF ANTIBODIES (Immunoglobulins): 1. IgG 2. IgA 3. IgM 4. IgE 5. IgD  Five Classes of Antibodies (Immunoglobulins) Antibodies – are large proteins also called as immunoglobulins found in the globulin fraction of the plasma proteins. 1. IgG – 75% of total Ig in the body source: interstitial fluids( serum and tissues), the most abundant antibody Function: assumes major role in blood-borne infections; activates complement system, neutralizes toxins and viruses, enhances phagocytosis, crosses placenta- responsible for immunity in the new born 2. IgA- 15%- source: blood, saliva, tears , breast milk, colostrum, mucus, prostatic, gastrointestinal and respiratory secretions. Function: protects against GI, GU, and respiratory infections; prevents absorption of antigen from food; adds protection against enteric virus to infants; passes to neonate thru breast milk  Five Classes of Antibodies (Immunoglobulins) 3. IgM : 10%, source: intravascular, second most abundant antibodies, the largest of the Ig in molecular size, first to appear in fetal life Function: appears as the first Ig produced in response to bacterial and viral infections, activates complement system 4. IgE : 0.004%, source: serum Function: responsible for allergic and hypersensitivity reactions, triggers release of histamine, combats parasitic infections 5. IgD : 0.2%, source: serum in small amount Function: possibly a regulatory antibody, acts as an antigen receptor or B cells, influences B-lymphocytes  ANTIGEN-ANTIBODY REACTION Antigen: a substance usually a protein that causes the formation of an antibody and reacts specifically with that antigen. Antigens are “markers” on the surface of cells that identify cells are being the body’s own cells (“self”) or as being foreign cells Antigens of foreign substances are identified as “intruders”, “invaders” or “non-self” Antibody: an immunoglobulin produced by lymphocytes in response to bacteria, viruses, or other antigenic substances. - it is specific to antigen - it includes agglutinins, opsonins, and precipitins  ANTIGEN-ANTIBODY REACTION 1. Agglutination – antibodies disarmed antigens by causing them to clamp together 2. Precipitation – this reaction occurs when antibody reacts with a soluble antigen resulting in an insoluble complex which then precipitates. 3. Neutralization – this occurs when antibody combines with toxins produced by some infectious agents to render them inactive and easier to engulfed and removed from the body. 4. Lysis – this is when antibody attacks cell membrane causing microorganisms to rupture. 5. Opsonization – in this process, the antigen-antibody molecule is coated with a sticky substance that also facilitates phagocytosis  CLASSIFICATION OF IMMUNITY I. SPECIFIC IMMUNITY B. CELLULAR IMMUNITY(cell-mediated) – when lymphocytes defend the body- T- lymphocytes are responsible for cellular immunity. These lymphocytes spend time in the thymus, wherein they are programmed to become T-cells. Activities and Major categories of T cells: a. Helper T cells – are activated upon recognition of antigens and stimulate the rest of the immune system. Directly and chemically stimulate the proliferation of other T cells and B cells b. Cytotoxic T cells – (Killer T cells) attack the antigen directly by altering the cell membrane and causing cell lysis (disintegration) and releasing cytolytic enzymes and cytokines. Release chemicals to activate phagocytes such as macrophages and neutrophils c. Memory T cells- have the ability to remember specific antigens and quickly activate immune response if they reappear on a future occasion d. Suppresor T cells- suppress actions and regulate number of b cells, cytotoxic and helper T cells (regulator) to avoid OA  Comparison of Humoral and Cellular Immunity HUMORAL IMMUNITY CELLULAR IMMUNITY B lymphocytes T lymphocytes Production of antibodies Production of sentisized Memory is present cells and lymphokines Examples are: bacterial Memory is present phagocytosis, Examples are: transplant anaphylaxis, hay fever rejection, delayed and asthma, immune hypersensitivity, graft complex disease, vs. Host disease, tumor bacterial and viral destruction, infection intracellular infections, viral, fungal and parasitic infections  CLASSIFICATION OF IMMUNITY II. NON-SPECIFIC IMMUNITY a type of immunity effective against any harmful agent entering the body. body’s natural immunity can discriminate friend from foe or self from non-self but cannot distinguish between agents & pathogens. NATURAL MECHANISM INCLUDES THE FOLLOWING; 1. PHYSICAL BARRIERS- intact skin and mucous membranes prevent pathogens from gaining access to the body. cilia of the respiratory tract filter & clear pathogens from the URT. 2) CHEMICAL BARRIERS- acidic gastric juices, enzymes in tears & saliva, sebaceous & sweat secretions attempt to destroy invading bacteria & fungi.  CLASSIFICATION OF IMMUNITY II. NON-SPECIFIC IMMUNITY NATURAL MECHANISM INCLUDES THE FOLLOWING; 3) BIOLOGIC RESPONSE MODIFIERS- a viricidal substance (INTERFERONS) counters viruses & activates other components of the immune system. INTERFERON- are glycoprotein induced in different cell types by appropriate stimuli, that counters viruses & activates other components of the immune system. AT LEAST (3) ARE RECOGNIZED; a) IFN-a or leukocyte- elaborated by leukocytes in response to viral infection or stimulation with double- stranded RNA. b) IFN-b – made by fibroblasts under the same condition. c) IFN-y or immune- produced by lymphocytes following mitogenic stimulation  CLASSIFICATION OF IMMUNITY II. NON-SPECIFIC IMMUNITY NATURAL MECHANISM INCLUDES THE FOLLOWING; 4) actions of WHITE BLOOD CELLS; a) neutrophils- are first to arrive in an inflammatory injury. b) eosinophils & basophils- are activated in response to allergic reactions & stress. c) granulocytes- release cell mediators, such as histamines, bradykinins, & prostaglandins, & engulf foreign toxins. d) monocytes or macrophages- function as phagocytic cells. To engulf, ingest, & destroy foreign toxins.  CLASSIFICATION OF IMMUNITY II. NON-SPECIFIC IMMUNITY NATURAL MECHANISM INCLUDES THE FOLLOWING; 5) INFLAMMATORY RESPONSE- this mechanism is elicited in response to tissue injury or invading organism. Mast cells release chemical mediators, which enhance the inflammatory & produce the typical signs of infection (redness, edema & itching) This action are important in ridding the body of harmful organism. It is also a key process of phagocytosis. 6) NATURAL KILLER CELLS- these lymphocytes are responsible for immune surveillance & host resistance to infection. 7) COMPLEMENT- this group of at least 20 circulating plasma proteins, made in the liver, are sequentially activated in the presence of an antigen.  FUNCTIONS OF COMPLEMENT: 1) CELL LYSIS- it causes cell rupture. 2) OPSONIZATION- involves making antigen more susceptible to phagocytosis by neutrophils & macrophages. 3) CHEMOTAXIS- induce migration of neutrophils macrophages to areas of high antigen concentration. 4) AGGLUTINATION- involves clumping of antigens. 5) NEUTRALIZATION- complement enzymes attack viruses & render them non-virulent. 6) ANAPHYLATOXIN PRODUCTION- certain complement proteins cause MAST cell degranulation, resulting in inflammation & possible allergic reaction.  INFLAMMATION - also called as “natural” immunity, it provides immediate protection against the effects of tissue injury & invading foreign proteins. - ability to produce an inflammatory response is critical to health & well being. - inflammatory response action s are important in ridding the body of harmful organisms. Inflammatory Response–considered as one of the major function of the non-specific immune system. It is the defensive reaction of the body intended to neutralize, control or eliminate the offending agent to prepare the site for repair Note: not all inflammation is a sign of infection (swelling from sprain, noninfectious inflammation allergic rhinitis, dermatitis, & other allergic reactions)  CARDINAL SIGNS OF INFLAMMATION 1.Redness (Rubor) 2.Heat (Calor)- results when vasodilation occurs after transient vasoconstriction that follows injury 3.Swelling (Tumor or Turgor)- results when vascular permeability increases, and plasma leaked into the inflamed tissues 4.Pain (Dolor)- – results when the pressure of fluids or sealing on nerve endings, and to the irritation of the nerve endings in chemical mediators released at the site 5.Loss of function (Functio Laesa)- related to pain and swelling  CELL TYPES INVOLVED IN INFLAMMATION: 1) NEUTROPHILS- a largest group of circulating leukocytes, serves as a powerful army of small cells as a first line of defense against invaders (esp. bacteria) in the blood & extracellular fluid. 2) MACROPHAGES- a mononuclear phagocyte system, the liver & spleen has the greatest numbers of these cells that plays more than one role in protecting against & tissue injury. a) these cells are important in immediate inflammatory response & stimulate the longer-lasting immune response(AMI & (CMI) b) inflammatory function is phagocytosis c) specific functions repair of injures tissues, presenting & processing antigen, & secretion of cytokines that help control the immune system.  CELL TYPES INVOLVED IN INFLAMMATION: 3) BASOPHILS- came from myeloid stem cell, & make up about 1% of the total circulating WBC count. Have granules containing many chemicals that act on blood vessels, includes; a) heparin- it inhibits blood & protein clotting. b) histamine- constrict small veins & respiratory smooth muscles. c) kinins- dilate arterioles & increase capillary permeability. d) serotonin- a vasoconstrictor, liberated by the blood platelets that inhibits gastric secretion & stimulate smooth muscles. e) leukotrienes- mediators of inflammation & roles in allergic reactions. 4) EOSINOPHILS- contains different substances, some induce inflammation when released. Enzymes from eosinophils degrade the vasoactive chemicals released by other leukocytes & can limit inflammatory reactions. This is why the number of circulating eosinophils increased during an allergic response. KEY PROCESS OF INFLAMMATION IS PHAGOCYTOSIS; - engulfing & destruction of invaders. - this action also rids the body of debris after tissue injury. - neurophils & macrophages are most efficient at phagocytosis.  (7) STEPS OF PHAGOCYTOSIS: 1) Exposure & invasion- for phagocytosis to start, leukocytes must first be damage. 2) Attraction- WBC (leukocytes) comes into direct contact with the target(invaders).Some substances act as chemical magnets that attract neutrophils & macrophages. These substances are called; chemotaxins or leukotaxins- secreted by a damaged tissues & blood vessels. 3) Adherence- the phagocytic cell (leukocyte) bind to the surface of the target, thru the process called opsonization or coating the target & makes it easier fro phagocytic cell to stick on it. Many substances can act as opsonins, some particles from dead neutrophils, antibodies, activated compliment components.  (7) STEPS OF PHAGOCYTOSIS: 4) Recognition- it recognizes the non-self for the phagocytic cell to start phagocytosis & it only start if the target cell is recognized as non-self or as a debris from damaged self cells. 5) Cellular ingestion- phagocytic cells bends its membrane around to enclose or engulf the target cell & a vacuole is formed. 6) Phagosome formation- the phagocyte granule inside the vacuole, where the granule breaks & release enzymes to destroy the ingested target. 7) Degradation- the phagosome digest the engulfed target, & the target is broken into smaller pieces until only small particles of debris remain. (3) STAGES OF INFLAMMATORY RESPONSE: 1) Vascular- early effects involve changes in blood vessels. When inflammation results from tissue injury, this stage has (2) phases; a) phase I- a rapid but short-term blood vessel constriction caused by trauma to blood vessel smooth muscle. It lasts only seconds & may be short that the person is unaware of it. b) phase II- hyperemia or blood flow to the area increases & edema or swelling forms at the site of injury or invasion. Injured tissues & the leukocytes in this area secrete histamine, serotonin & kinins that constricts the small veins & dilate the anterioles in the area of injury. 2) Cellular exudate- neutrophilia or there is an increased number of circulating neutrophils occurs along with the formation of exudate or commonly known as pus. At this stage neutrophil is active under the influence of cytokines, counts can increase to 5 times w/in 12 hours after the onset of inflammation. (3) STAGES OF INFLAMMATORY RESPONSE: 3) Tissue Repair & Replacement- some of the WBC involved in inflammation start the replacement of lost tissues or repair of damaged tissues by inducing the remaining healthy cells to divide  STAGES OF SPECIFIC IMMUNE RESPONSES: 1) Recognition- circulating lymphocytes & macrophages recognize foreign material or antigen as non self. 2) Proliferation- sensitized lymphocytes proliferate, differentiate, & mature into respective T & B cells. swelling of the lymph nodes in the neck in conjunction with a sore throat & an increase in WBC count is an indication of an active immune response. 3) Response- antibody is produced w/ specific T-cell action - Humoral & cellular responses becomes activated. The body produce memory cells. - B-cell w/ the help of helper T-cell produce antibodies. 4) Effector- antigen is destroyed by antibody. Complement is activated & lymphokines released, & all work to destroy foreign materials. FACTORS AFFECTING IMMUNE RESPONSE: 1) age- thymus gland & T-cell deteriorates w/ increasing age. immune response are most efficient at 20’s- 30’s. 2) emotional stress- study shows that stress affect person’s cellular immunity. It decreases lymphocyte stimulation. 3) Physical factors- it includes nutrition & hormone levels have been implicated in immune dysfunction.  TYPES OF IMMUNITY: A. NATURAL-NATIVE IMMUNITY – innate or genetically or primary immunity; provides a nonspecific response to any foreign invader, regardless of the invaders composition. - the basis of natural defense mechanism is merely the ability to distinguish between self and non- self B. ADAPTIVE or ACQUIRED (ACTIVE AND PASSIVE) IMMUNITY – or secondary immunity is an immunologic response acquire during life but not present at birth; involved humoral and cellular (cell-mediated) immunologic responses. The immunity that the person’s body makes (or can receive) as an adaptive response to invasion by organisms or foreign proteins.  ADAPTIVE or ACQUIRED IMMUNITY: Two Types of Acquired Immunity: a. ACTIVE ACQUIRED IMMUNITY: it is developed by the person’s own body, the person develop his own antibodies; takes 10 to 14 days to develop, it is permanent, and body cells undergo change Active acquired immunity could either be: 1. Natural (naturally acquired) – having contact with antigen naturally such as getting sick or frequent exposure to smaller doses of microorganisms like: chickenpox, measles, mumps 2. Artificial (artificially acquired) – acquiring antigen through vaccines or toxoids, destroyed or attenuated microorganism-causing disease like in BCG, DPT and POLIO stimulating the immune system to produce anti- bodies without harming the host  ADAPTIVE or ACQUIRED IMMUNITY: b. PASSIVE ACQUIRED IMMUNITY: temporary immunity; antibodies are not produced by an individual but are obtained from another source and can be obtained either naturally or artificially Passive acquired immunity could either be: 1. Natural-Passive (acquired) Immunity- bestowed when the placental transmission of antibodies from mother to fetus occurs; for few months after birth infant is protected from all antigens to which the mother has been exposed, also present in colostrum, if breast-fed, the immunity may last longer 2. Artificial-Passive (acquired) Immunity- bestowed when anti- serum, such as immune serum gamma globulins is administered such as immune sera (rabies), tetanus(antitoxin), snake bites(anti-venom)- passive immunity is never permanent (2-3 weeks only)  IMPORTANT ROLES OF NURSES WITH IMMUNIZATION: 1. Administration of vaccine, vaccine’s correct dose using proper injection techniques. 2. Assessment and management for complications of immunizations. generally these reactions are minor; > low grade fever > discomfort at injection site > irritability & > malaise - however some individuals develop serum sickness or anaphylaxis, which requires emergency intervention. 3. Teaching the public about the importance & timing of vaccination.  BASIC CONCEPT ON INFECTION: - Infection or infectious disease is a significant health problems. - Infection acquired in health care agencies as an example affects 5% of patient admitted in the hospital. - infectious disease carries important professional, legal, ethical, & financial implications for health care providers. INFECTION- (colonization) is the presence of microorganisms w/in a host. - not all infection cause a disease. Some bacteria, for example normally inhabit the human body as part of the “resident” or “normal flora”. The organism live symbiotically with the human host. - when an infection does cause a pathologic process, the person is said to have an infectious disease.  CHAIN OF INFECTION: - It refers to the process by which an infectious agents; - is transmitted from environment to host - invades the host & - causes disease types of infectious agents a) Bacteria b) Viruses- specific agent of infectious disease c) Rickettsiae- a gram negative bacteria usually occur intra-cytoplasmically in lice, fleas, ticks, & mites; pathogenic species are parasitic on man & other animals. d) Protozoa- a phylum of the animal kingdom, including all of so-called unicellular forms, consisting of a single functional cell unit.  CHAIN OF INFECTION: types of infectious agents e) fungi- a division of plant like organisms growing in irregular masses (fungus, mushroom) f) Helminths- an intestinal vermin form parasite. TYPES OF INFECTION: 1) communicable disease- 2) nosocomial infection- infection acquired in health care agency. 3) opportunistic infection- opportunistic organism usually cause disease only when the person’s defense are weakened.  HOW PATHOGENS CAUSE A DISEASE: 1) growing & multplying w/in the host 2) evading host defenses 3) penetrating & spreading thru host tissues & 4) produce a toxins - Microbes evade or destroy host defenses by encapsulating themselves w/in protective coatings that either prevent phagocytosis or allowing microbes to survive & colonize. - Microbes produce substances such as leukocidin that kill phagocytes. - Microbes spread thru host tissues by secreting enzymes that damage certain tissues, these enzymes includes; a) collagenase- destroys collagen proteins of connective tissue b) kinase- capable of dissolving fibrin clots c) hemolysins- destroy RBC’s d) mucinase- digests mucin produced by many mucosal cells.  RESERVOIR or source of infection - a place where organisms can thrive and multiply. a) Human- is the reservoir of disease that are more dangerous to humans than other species. b) Animal- responsible for infestations with trophozoites, worms etc. c) Non-animal- street dust, garden soil, fomites.  Mode of Transmission The mode how the pathogen could be transferred from one host to another a. By contact transmission 1. Direct contact- person to person; horizontal vs. vertical 2. Indirect contact- usually an inanimate object 3. Droplet contact- coughing, sneezing, or talking, secretions and excreta b. By vehicle route 1. Food-salmonellosis 2. Water- shigellosis, legionellosis 3. Drugs- bacteremia, infusion of contaminated infusion product 4. Blood- hepatitis B, HIV  Mode of Transmission c. Airborne transmission 1. Droplet nuclei- residue of evaporated droplets that remain suspended in air 2. Dust particles 3. Organisms shed into environment from hair, skin, wounds or perineal area d. Vectorborne transmission 1. Via contaminated or infected arthropods such as flies, mosquitoes, cockroaches, ticks and others 2. Livestock 3. Rodents 4. Birds and other domesticated animals  Portal of Entry Mode of entry of organisms into human body 1. Gastrointestinal tract 2. Respiratory tract 3. Genitourinary tract 4. Direct introduction of pathogens into mucous membrane, tissues, cavity, blood vessels, and skin  Susceptible Host Illness following entrance of infection into the body defends on: 1. age, sex, genetic background 2. Nutritional status, fitness, environmental factors 3. General physical, mental and emotional health 4. Absent or abnormal immunoglobulins 5. Status of hematopoietic system, efficacy of reticuloendothelial system 6. Presence of chronic diseases such as DM, lymphoma, leukemia, neoplasia, granulocytopenia, uremia 7. Patient treated with certain antimicrobials, corticosteroids, irradiation and immunosuppressive agents CLINICAL STAGES OF ACUTE INFECTIOUS DISEASE: I. INCUBATION PHASE- agents invades the host & establishes self. If the microbes survives & replicate w/in the host, disease will likely to follow. Usually 1-2 days, in w/c the person develops the earliest symptoms of infectious dse (mild fever & lethargy) II. PRODROMAL PHASE- organisms disseminates throughout the body or multiplies at a localized site. III. ACUTE PHASE- interaction between host & infectious agent reaches full intensity. Symptoms of acute illness usually correspond to the site & degree of infection. eq. characteristic of sore throat will accompany acute staphylococcal pharyngitis. IV. RECOVERY PHASE- begins with the declines of symptoms & an improvement of health. APPLICATION OF NURSING PROCESS: ASSESSMENT: I. Health history- a) elicit description of the client’s present illness & chief complaints, such as; > lack of energy > light-headedness > frequent bruising b) encourage patient to elaborate, & ask about associated signs & symptoms; > lymph node enlargement > weakness or joint pains > development of a rash > abnormal bleeding > slow healing sores > vision disturbances > fever > changes in elimination patterns APPLICATION OF NURSING PROCESS: ASSESSMENT: I. Health history- c) family history of cancer or hematologic or immune disorders. d) ask if patient undergone procedures that affect the immune system, such as; > blood transfusion > organ transplant e) ask about patient home & work environments to determine if patient is being exposed to hazardous chemicals or other toxic agents. f) ask if patient had surgery that involves removal of the spleen, lymph nodes, or thymus. g) ask about patient current medications, some meds suppresses immune response. Eq. corticosteroid & chemotherapy. h) ask about any chronic diseases such as arthritis, diabetes or renal disease.  CARDINAL SIGNS & SYMPTOMS INDICATING ALTERED IMMUNITY: a) General: > recurrent infections > seasonal symptoms > weight loss > fever b) Head: > itching, burning, watery eyes, visual problems, & eye infections. > recurrent ear infections > rhinitis & sneezing c) Respiratory system: > cough > dyspnea > recurrent URT infection > note for position assume to ease breathing, during asthma attack patient may sit up to use every accessory muscle of respiration.  CARDINAL SIGNS & SYMPTOMS INDICATING ALTERED IMMUNITY: d) Cardiovascular system: > pain > extreme pallor & then cyanosis of extrimities brought on by cold exposure (raynaud’s phenomenon) may caused by SLE or scleroderma > peripheral pulses must be regular & symmetrical, weak irregular may indicate anemia. Note: scleroderma- thickening of the skin caused by swelling of fibrous tissue, w/ eventually atrophy of the epidermis, a manifestation of progressive systemic sclerosis.  CARDINAL SIGNS & SYMPTOMS INDICATING ALTERED IMMUNITY: e) G.I. system: > nausea & vomiting > diarrhea > bowel sound increased w/ autoimmune disorders that causes diarrhea. > bowel sound decreased w/ scleroderma & autoimmune disorders that causes constipation. > hepatomegaly can accompany many immune disorders, that causes congestion by blood cell overproduction or by excessive demand for cell destruction.  CARDINAL SIGNS & SYMPTOMS INDICATING ALTERED IMMUNITY: e) G.I. system: > abnormal tenderness may result from infections. > inspect the anus which should be pink & puckered without inflammation or breaks in the mucosa surface. f) Genitourinary system: > recurrent UTI > dysuria & hematuria > inspect the urinary meatus, patient w/ WBC deficiency or an autoimmune deficiency, the external genitalia may be focal points for inflammation w/c is commonly accompanied by discharge or bleeding related to infection.  CARDINAL SIGNS & SYMPTOMS INDICATING ALTERED IMMUNITY: g) Musculoskeletal System: > weakness & fatigue > inability to perform ADL’s > ask patient to perform simple maneuvers such as; walking, standing up, & bending over. It should be done effortless. > joint ROM particularly hands, wrist, & knees. > palpate joints to check for swelling, tenderness, & pain. Autoimmune disorders such as SLE can limit ROM & cause joint enlargement. > palpation reveals bone tenderness, caused by bone marrow hyperactivity a compensatory mechanism for oxygen- carrying deficits prevalent in anemia. May also results from a leukemic or immuno-proliferative disorder such as, plasma cell myeloma that causes cell packing In the marrow  CARDINAL SIGNS & SYMPTOMS INDICATING ALTERED IMMUNITY: h) Neurologic system: > disorientation > altered LOC > paresthesia- abnormal sensation such as burning, pricking, tickling, or tingling. > impaired neurologic function may occur secondary to hypoxia or fever. > if bleeding occurs w/in the cranial vault disorientation, progressive loss of consciousness, changes in motor & sensory capabilities, changes in pupillary responses, & seizures may result. > altered mentation, depression or psychosis may be experience by patient w/ SLE. APPLICATION OF NURSING PROCESS: ASSESSMENT: 2) Explore the client’s health history for risk factors, it includes; a) not keeping up-to-date immunization b) exposure to infectious disease c) exposure to pollens, insects, & allergens  APPLICATION OF NURSING PROCESS: Physical examinations- besides P.E. examine the spleen, & lymph nodes for enlargement ( the only accessible immune system structure) it includes general appearance, v/s, & related body structures & systems, the effects of immune disorders are far- reaching & may materialize in several body system. ASSESSING APPEARANCE & VITAL SIGNS: a) begins by observing patient physical appearance > look for signs of acute illness, such as grimacing or profuse perspiration & of > chronic illness such as emaciation ( wasting becoming abnormally thin from extreme loss of flesh) & listlessness. APPLICATION OF NURSING PROCESS: ASSESSING APPEARANCE & VITAL SIGNS: b) determine whether the patients stated age & appearance agree. > chronic dse & nutritional deficiency related to immune dysfunction may make the patient looks older than he/she actually is. c) observe patient facial features > look for edema, grimacing or lack of expression > non-pitting edema commonly accompanies myxedema a severe hypothyroid state, thyroiditis commonly causes hypothyroidism. d) measure patient height & weight > weight loss may loss may result from anorexia or other G.I. problems related to immune disorders. e) observe patient’s posture, movements & gait > any deviations may indicate joint, spinal, or neurological changes stemming from an immune disorders.